The invention relates to a chair having an adjustable seat and an ergonomically cooperating foot support to be used at high tables, especially in schools.
Within the school, tall pupil tables are tried out in order to avoid load damages affecting teachers bending forwardly during guidance, together with tall chairs to prevent back problems affecting pupils, giving them the possibility of changing between usual "passive" sitting position (90.degree. between calf (lower leg) and thigh on the one hand and between thigh and body on the other hand) and a more open "active" sitting position (120.degree. between calf and thigh respectively between thigh and body).
Such a work-place has been developed by DR. A. C. Mandal, Denmark, and is produced i.a. by MK Stalm.o slashed.obler a.s., DK-5500 Middelfart. Disadvantages consist in that many chair variants are required; the foot support of the chair for "passive" sitting position must be adjusted separately; the table must be adjusted vertically separately; the various levels of the tables differ, and the foot support of the table for "active" sitting position must be adjusted separately.
The same favourable working position is achieved by teacher and pupil if all adjustments are gathered on the chair, using tables positioned at one fixed level. Tables without adjustments are labour-saving and prevent risks for errors. Equal table level is necessary upon grouping.
Such a chair is disclosed in Norwegian patent specifications Nos. 135,118 and 150,743, now cancelled. The disadvantage of this chair is that the vertical distance from seat to tabletop as well as the vertical distance from foot support to seat must be adjusted separately; the chair does not offer any possibility of sitting in an open "active" position, and it is only intended for usual dining table levels.